4 Experiment 5.1 | Chemistry Form

Ravi carefully dropped a few granules of zinc into the next tube. For a moment, nothing. Then, a miracle. The deep blue colour began to bleed away from the zinc, as if an invisible eraser was moving upwards. Simultaneously, a reddish-brown dust started to bloom on the surface of the zinc granules, like rust forming in fast-forward.

It was a Thursday afternoon, and the Form 4 Science lab smelled of antiseptic and old wood. Maya, Lin, and Ravi huddled over their workstation, a neat row of four test tubes clamped to a metal stand. Their teacher, Puan Aishah, had given them a puzzle.

“Correct. And the reactivity series order from this experiment?” chemistry form 4 experiment 5.1

The solution turned from vibrant blue to a pale, cloudy colourless. The reddish-brown solid was pure, elemental copper. Zinc was the hero.

“Exothermic,” Maya whispered, recording the temperature rise. The magnesium was even more reactive than zinc. It had ripped the copper from the solution with such force that it generated heat. Ravi carefully dropped a few granules of zinc

Later, as they washed the test tubes, Ravi looked at the reddish-brown copper residue stuck to the glass. “It’s like a chemical war,” he said. “The strong kick the weak out of their homes.”

Ravi, whose fingers were always a little too eager, held a small coil of magnesium ribbon. It looked like a piece of dull, grey tinsel. “This looks harmless,” he smirked. The deep blue colour began to bleed away

“No reaction,” Maya noted, scribbling in her book. “Copper + copper sulphate → no change. That means copper is low in the reactivity series. It can’t kick itself out of its own salt.”

“Last one,” Ravi whispered, holding the magnesium ribbon with a pair of tongs. Puan Aishah wandered over. “Careful, Ravi. This one is dramatic.”